Conventionally, for an insulated covering material for an insulated wire used in carrying out wiring of parts for an automobile and electric/electronic equipment and other parts, there is widespread use of a vinyl chloride resin composition to which a halogenous flame retardant is added.
However, there is a problem that the insulated covering material includes halogen elements, so that it emits harmful halogenous gas into the atmosphere incase of car fire or at the time of combustion for disposing of electric/electronic equipment by incineration, causing environmental pollution.
Therefore, from the viewpoint of reducing loads on the global environment, the insulated covering material has recently changed from the vinyl chloride resin composition to a polyolefin resin composition, which is prepared by adding a metallic hydrate such as magnesium hydroxide to polyolefin such as polyethylene.
As the insulated wire using the polyolefin resin composition for the insulated covering material, Japanese Patent Application Unexamined Publication No. H7-176219, for example, discloses an insulated wire using a composition which includes 30 to 100 parts by weight of magnesium hydroxide with respect to 100 parts by weight of a polymer blend of straight-chain polyethylene and carboxylic modified polyethylene.